494 Mr. C. T. Regan on the 



1. Gyropleukodus. 



Gyropleurodus, Gill, Proc. Ac. Philad. 1869, p. 482. 

 'Tropidodus, Gill, I, c. 



Anterior teeth cuspidate. Lateral teeth carinate, longer 

 but not much broader than the anterior ones ; jaws rounded 

 anteriorly, the rami divergent from the short symphyses ; 

 supraorbital ridges ending abruptly a little beliind the orbits. 



Three species. 



Synopsis of the Species. 



I. Leng-th of first gill-opening equal to its distance from the third. 



Origin of first dorsal a little in advance of the posterior 



end of the base of pectoral 1. francisci. 



Origin of first dorsal far behind the base of pectoral 2. quoyi. 



II, Length of first gill-opening not less than its distance 



from the fourth 3. (jaleatus. 



.1 . Gyropleurodus francisci. 



Cestracion francisci, Givavd, Proc. Ac. Philad. 1854, p. 196; Giinth. 



Cat. Fisii. viii. p. 416 (1870). 

 Gyropleurodus francisci, Gill, Proc. Ac. Philad. 1862, p. 492 ; Jord. & 



Everm. Bull. U.S. Nat. Mus. xlvii. 1896, p. 20. 

 liefer odonius francisci, Macleav & Macleay, Proc. Linn, Soc. N. S. 



Wales, iii. 1878, p. 315, pi. xxvi. 



Supraorbital ridges strong, nearly vertical. Origin of first 

 dorsal a little in advance of the posterior end of the base of 

 pectoral. Small rounded blackish spots on head, body, and 

 fins. 



Hah. California. 



In the British Museum two specimens, 195 and 330 mm. 

 in total length. 



2. Gyropleurodus quoyi. 



Cestr avion quoyi, Fr^minv. Mag. Zool. 1840, pi. iii. ; Giinth. Cat. Fish. 



viii. p. 416 (1870). 

 Cestracion pantherinus, Valenc. Zool. ' Venus,' Poiss. p. 320, pi. x. 



fig. 2 (1855). 

 Jleterodontus quoyi, Macleay & Macleay, Proc. Linn. Soc. N. S. Wales, 



iii. 1878, p. 316. 

 Gyropleurodus quoyi, Jord. & Everm. Bull. U.S. Nat. Mus. xlvii. 1896, 



■p. 21. 



Evidently closely allied to C. francisci, but with larger 

 spots and with the first dorsal much further back, its origin 

 far behind the base of the pectoral. 



Hah. Galapagos Islands. 



